America is at war – in Iraq, and against a global Islamist terror network committed to the nation’s destruction.

McCain indisputably understands the nature of the threat, and what it will take to defeat it.

And he will not flinch.

We have long admired the senator. In 2000, we endorsed his presidential candidacy over that of the eventual winner, George W. Bush. And we support him today for many of the same reasons.

He is a proven leader, and a man of integrity.

A naval aviator shot down over North Vietnam and held as a POW, McCain knew that freedom was his for the taking. All he had to do was denounce his country.

He refused – and, as a consequence, suffered years of unrelenting torture.

It was a test of character, and injuries suffered during the ordeal persist – constant reminders that, though millions around the globe admire America, too many others despise this country simply because it is a beacon of freedom and hope.

And they pose a mortal threat.

Yet even as he insists that the use of force must remain on the table, he insists that “it is no substitute for diplomacy.”

He is no hothead, in other words.

True, McCain is an occasional maverick on such core Republican issues as campaign-finance reform – and we’ve taken him to task for that.

On illegal immigration – a most difficult issue – he has taken a softer view than most Republicans, officially disdaining amnesty but supporting a “path to citizenship” for illegals already here. (Indeed, he has said that the presence of 12 million illegals here constitutes “de facto amnesty.” And he’s not wrong.)

He also – happily – has reversed his initial opposition to the Bush tax cuts, saying that position was “a mistake.”

Parts of his record, in short, are problematic for many Republicans. But the true believers must understand that in a democracy, compromise is necessary.

What of McCain’s chief opponent, former Massachusetts Gov. Mitt Romney? Well, a four-year stint in the Boston statehouse constitutes the sum total of his governmental experience. That simply is not enough.

Come November, McCain’s experience would stand in sharp contrast to Barack Obama’s sparse resume. And his candor, character and honor would be the antithesis of a Clinton II candidacy.

McCain has spoken of serving “a cause greater than self-interest.”

That cause, he said, “has been my country, which I have served imperfectly for many years but have loved without any reservation every day of my life.”

John McCain brings more than patriotism to the table. But he knows what comes first.